CRL's Brite Zinc Flush or Surface Mount Standards are preferred by many mill, showcase, and furniture manufacturers and installers because they can be set in flush or mounted on the surface of the woodwork. This narrow Standard shows less metal and is not as conspicuous as wider standards. Mounting screw holes are spaced 6" (152 mm) on center. Shelves are instantly adjustable every 1/2" (12.7 mm). Due to the diverse types of substrate materials, the selection of mounting screws is the responsibility of the installer.